Texas Instruments TI-57 LCD
Datasheet legend
Ab/c:
Fractions calculation
AC: Alternating current BaseN: Number base calculations Card: Magnetic card storage Cmem: Continuous memory Cond: Conditional execution Const: Scientific constants Cplx: Complex number arithmetic DC: Direct current Eqlib: Equation library Exp: Exponential/logarithmic functions Fin: Financial functions Grph: Graphing capability Hyp: Hyperbolic functions Ind: Indirect addressing Intg: Numerical integration Jump: Unconditional jump (GOTO) Lbl: Program labels LCD: Liquid Crystal Display LED: Light-Emitting Diode Li-ion: Lithium-ion rechargeable battery Lreg: Linear regression (2-variable statistics) mA: Milliamperes of current Mtrx: Matrix support NiCd: Nickel-Cadmium rechargeable battery NiMH: Nickel-metal-hydrite rechargeable battery Prnt: Printer RTC: Real-time clock Sdev: Standard deviation (1-variable statistics) Solv: Equation solver Subr: Subroutine call capability Symb: Symbolic computing Tape: Magnetic tape storage Trig: Trigonometric functions Units: Unit conversions VAC: Volts AC VDC: Volts DC |
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Texas Instruments TI-57 LCD
The TI-57 LCD is another example of an inexplicable trend at Texas Instruments in the early 1980s to produce new calculator models that are less functional than their predecessors.
The TI-57 was a good calculator, but it had limited program and memory capacity. So what do the engineers of Texas Instruments do? They create a successor with even less memory! Whereas the TI-57 had 50 program steps and 8 memory registers, the TI-57 LCD has only 49 program steps or 7 memory registers; each memory register "steals" 7 steps of program memory, when the calculator's memory is repartitioned. This severely limits the utility of this machine.
My first TI-57 LCD was, sadly, a sick puppy. Although it looked pristine, it was not functional. Most of the time, its display showed complete gibberish; sometimes I could wreak something apparently sensible out of it, like the word CALC shown on the right here. Since then, fortunately, I was able to obtain some functional copies of this machine, including machines with an alternate paintjob.
Given this machine's limited memory, some otherwise simple algorithms are difficult to implement on it. My favorite example, the Gamma function, is no exception. On implementation that goes easy on the programming steps actually computes the incomplete Gamma function. Technically, elegant, this algorithm is nevertheless a pain in the butt to use: the TI-57 LCD is a very slow machine!
61.01 00 STO 1
45 01 yx
51 02 x-t
61.00 03 STO 0
55 04 ÷
71.00 05 RCL 0
55 06 ÷
71.01 07 RCL 1
-32 08 INV lnx
95 09 =
61.02 10 STO 2
51 11 x-t
23.01 12 LBL 1
71.01 13 RCL 1
61.65.02 14 STO× 2
01 15 1
61.85.00 16 STO+ 0
71.00 17 RCL 0
61.55.02 18 STO÷ 2
71.02 19 RCL 2
85 20 +
51 21 x-t
65 22 ×
51 23 x-t
01 24 1
95 25 =
51 26 x-t
-26 27 INV x=t
22.01 28 GTO 1
13 29 R/S
21 30 RST